Special features: Ultra-high resolution

Applications

Aerosol research

Atmospheric and air pollution monitoring and research

Coalescence and nucleation research

Superior Resolution

UHSAS accurately sizes even the smallest particles. The graph at right shows the results of a test conducted with 95 nm and 104 nm standard PSL particles. Although these particle diameters are only 9 nm apart, the UHSAS has correctly identified two distinct particle peaks.

Other Advantages

Eliminates sizing uncertainty associated with scattering spectrometers that measure at sizes larger than the excitation wavelength

Counts up to 3,000 particles/second

Uses aerosol spectrometry technique with two detection systems: a primary, highly sensitive APD-based system to size smaller particles, and a secondary PIN photodiode system to size larger particles

Compensates for small drifts in laser power via automatic gain control

Features an on-board computer and powerful LabVIEW software to facilitate real-time data analysis

Software

The UHSAS comes with LabVIEW-designed software that provides a user-friendly virtual instrument panel for the control and data display of the UHSAS. For instance, the program enables the user to do the following tasks:

Start data recording and sampling

View a histogram of particles binned by diameter, by transit time, or by peak optical signal

Set boundaries for the histogram bins

Control sample flow and monitor temperature, pressure, and laser current

Calibrate the instrument

How It Works

A laser illuminates particles, which scatter light that is collected by two pairs of Mangin optics. One pair of optics images onto a highly sensitive avalanche photodiode (APD) for detecting the smallest particles. The other pair images onto a low-gain PIN photodiode for detecting particles in the larger size range of the instrument. Each detector is amplified in a current-to-voltage stage that feeds into the analog electronics system. The amplification allows the system to detect particles as small as 65 nm.